Keelhaul/ˈkiːlhɔːl/ Definition 1 of 2Pro Tip 1/3Historical Brutality Originally a brutal punishment at sea, imparting danger and harshness. Tales of pirates often mention the cruel method of keelhauling. Pro Tip 2/3Literal Interpretation Literally dragging under a ship's keel; involves the concept of maritime. In the navy, you'd fear being keelhauled for serious offenses. Pro Tip 3/3Extreme Consequence Indicates a punishment beyond the norm, very severe and rare. To deter mutiny, the captain threatened to keelhaul the first to disobey.